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it is possible that you have males of two different species of ancistrus (there are about 3 almost identical "bristlenose" types in the trade), which would account for them looking different and having different bristles. From what I understand, while in some ancistrus species females will have bristles almost as long as the males around the front and sides of their head, no female ancistrus show brisles on top of the lip gong up to the eyes.